// ETGenerator.cs
//
// Copyright (c) 2008 Jérémie "Garuma" Laval
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
//

using System;
using System.Collections.Generic;

using Irony.Runtime;
using Irony.Compiler;

using Microsoft.Linq.Expressions;
using Microsoft.Scripting;

namespace Bechamel
{
	public class ETGenerator
	{
		Dictionary<string, ParameterExpression> defines = new Dictionary<string, ParameterExpression>();
		List<ParameterExpression> parameters;
		
		public IEnumerable<ParameterExpression> Defines {
			get {
				return defines.Values;
			}
		}
		
		public Expression GetExpressionFromAst(AstNode node)
		{
			BechamelNode bNode = node as BechamelNode;
			if (bNode == null)
				Console.WriteLine("AST is mal formed -> An AST node ({0}) isn't a BechamelNode", node.GetType().ToString());

			return bNode.GenerateExpression(this);
		}

		public Expression GetExpressionFromAst(AstNode node, List<ParameterExpression> ps)
		{
			parameters = ps;
			BechamelNode bNode = node as BechamelNode;
			if (bNode == null)
				Console.WriteLine("AST is mal formed -> An AST node ({0}) isn't a BechamelNode", node.GetType().ToString());

			Expression result = bNode.GenerateExpression(this);
			parameters = null;

			return result;
		}

		public void ReferenceDefine(string name, ParameterExpression p)
		{
			if (name != null && p != null)
				defines.Add(name, p);
		}

		public ParameterExpression GetDefine(string name)
		{
			ParameterExpression p;
			defines.TryGetValue(name, out p);

			return p;
		}

		public bool TryGetParameter(string name, out ParameterExpression param)
		{
			param = null;
			
			if (parameters == null)
				return false;
			
			ParameterExpression result = parameters.Find(e => e.Name == name);
			param = result;

			return result != null;
		}
	}
}
